Die-casting machine



Dec. 11 1923. 1,476,765

T. E. MURRAY, JR, ET AL DIE CASTING MACHINE Filed June 1. 1921 2 Sheets-Sheet 1 v o J Q T/imasEWl/rmyJr 5m mtow Hem" 5. Ho/m s 33) rheh 61 oz Dec. 11 1,923. 1,476,765

T. E. MURRAY, JR., ET AL DIE CASTING MACHINE Filed June 1. 1921 2 Sheets-Sheet 2 56 5 g 49 5 I i a; m /6 m /6 Thamas Z'. WurmyJ/t Ewvmtoz Hem" 5'. Holmes Patented Dec. 11, 1923.

UNITED STATES THOMAS E. MURRAY, JR., 015 BROOKLYN,

1,476,765 FATEN'T OFFICE.

AND HENRY S. HOLMES, OF NEW YORK,

N Y.; SAID HOLMES ASSIGNOB OF HIS ENTIRE RIGHT TO THOMAS E. MURRAY,

BROOKLYN, NEW YORK.

DIE-CASTING MACHINE;

Application filed June 1,

To all whom it may concern:

Be it known that we, THOMAS E. MURRAY, Jr., and HENRY S. HOLMES, citizens of the United States, and residents of the city of Brooklyn, county of Kings, and State of New York, and of the city, county, and State of New York, respectively, have invented certain new and useful Improvements in Die-Casting Machines, of which the following is a specification.

Our invention provides a die casting machine having certain advantages in economy of operation and in other respects referred to in detail hereinafter. The accompanying drawings illustrate our invention.

Fig. 1 is a longitudinal section of the fire box, melting pot and dies and adjacent parts with other parts in elevation;

Fig. 2 is a cross-section on the line 2-2 of Fig. 1;

Fig. 3 is a cross-section on the line 33 I of Fig. 1;

Fig. 4 is a diagram of the electric circuits.

Referring to the embodiment of the invention illustrated, 1 is a fire box which carries a melting pot 2 containing the metal to be cast. In the melting pot a dipper 3 rocks about a pivot 4 mounted on the fire box. The dipper carries an upward cylindrical extension 5 in which is a piston 6. When the dipper is rocked down it fills with metal, and when it rocks up its mouth or nozzle comes into position for engagement with a pair of dies, 2. fixed die 7 and a movable die 8, the nozzle of the dipper registering with an opening between the dies; so that when the piston 6 is next advanced it forces the metal under pressure into the dies.

The dipper is rocked by means of a double acting solenoid 9 having a core 10 connected at the upper end to a link 11 which is connected to an arm 12 on the upper part of the dipper.

The fixed die 7 is mounted on a plate 13, and the movable die 8 on a piston 14 which moves in a bearing 15 which is cast integrally with the casing of a double acting solenoid 16, to which the plate 13 is fixed by means of the tie-rods and adjusting nuts shown. This casing is provided at the bottom (Fig. 2) with flanges 17 which slide in gibs or guideways 18 on a table 19 arranged to rock about a pivot 20 (Fig. 1)

1921. Serial N0. 474,194.

mounted on the base 21 of the machine. The table 19 carries also a double acting solenoid 22 which has a plunger 23 adjustably fastened by means of bolts 24 and clamping nuts to lugs 25 on the sides of the magnet 16. Thus the magnet 16 serves to open or close the dies and the magnet 22 serves to shift them (with the magnet 16) to bring the dies to the casting position shown or to retract them from over the hot metal so as to facilitate the removal of the casting. The solenoids 16 and 22 which serve to close the dies are arranged to exert their maximum pressure at the end of the closing stroke.

The table 19 is tilted by means of a double acting solenoid 26, the core or plun er 27 of which is connected by links 28 wit ears on the under side of the table.

The piston 6 operating in the cylinder at the upper end of the dipper is carried on the lower end of the core 29 of a double acting solenoid indicated as a whole b the numeral 30 and mounted on the flang upper end of the cylinder 5.

Preferably the various motors or magnets for securin the necessary movements of the parts 0 the machine are double acting solenoids of the type illustrated in Fig. 3.

The casing consists of two iron frames bolted together. A block 31 of soft iron is clamped between the two frames and has a hole in the middle through which slides a brass rod 32 carrying an upper soft iron plunger 33 and a simllar lower plunger 34,

these plungers passing through the coils 35' and 36 respectively and through brass bushings 37 and 38 in the ends of the iron frames. Each coil consists of many turns of insulated copper wire wound on brass spools 39 and 40. When the upper magnet coil is energized, the plunger 33 is drawn into it and the lower plunger 34 forced out, and when the lower coil is energized the cores move in the opposite direction. On the upper part of the casing are contact points 42 and 43 insulated from the casing and connected to the circuit in a manner hereinafter described and adapted to be bridged by a contact member 44 carried by the upper plunger, when the latter is drawn into the magnet. Similar contacts 45 and 46 insulated and mounted on the lower part of the casin are-adapted to be bridged by a contact 4 carried on the lower plunger 34. With this underava-me standing of the construction of the solenoids, and assuming all of them to operate in the same way, the diagram Fig. 4 shows the connections between them by which they are caused to operate forward and backwardin proper sequence to secure the successive steps of casting the metal and restoring the machine to starting position. a

The main line switch 48 connects the machine with the' conductors 49 and 50 from the source of supply. This switch will ordinarily remain closed during the working day and will be opened only when the machine is to be out of use for some time. The hand switch 51 serves to start the operation of the machine. This is shifted alternately to the contacts 52 and 53 for successive operations of casting and resetting the machine.

Supposing it moved up to the contact 52 for the first operation, it will energize the coil 9 of the dipper-tilting solenoid, which at this time is charged wlth molten metal, but is tilted with its mouth in the molten metal in the pot. The current passes through the line 54 thence through the coil and out by the connection 58 to the line 56 which goes to the line Switch. This draws down the core of the solenoid and lifts the dipper to the operative position.

At the same time it pulls down a bridge piece 9 into engagement with contacts 9 and 9 and causes the current to pass through wire 59 to the right hand coil 16 of the solenoid 16, the current passing out through the connection 60 to the main line switch. This advances the plunger of the solenoid 16 to the left and moves the movable die 8 against the fixed die 7.

At the same time the bridge 16 carried by the plunger of this magnet is brought up against the contacts 16 and 16 and the cur rent passes through them to the line 61 and to the right hand coil 22 of the right hand solenoid 22, the current passing out by the line 62 to the main line switch. This pushes the plunger 23 to the left and also the solenoid 16, and the movable die 8 pressed against the fixed die is carried therewith.'

At the same time a bridge 22 carried by this plunger is brought up against the contacts 22 and 22 and the current passes by the wire 63 to the upper coil 26 of the solenoid 26 and out by the wire 64. This draws down the plunger 27 and tilts the table to bring the closed dies on the nozzle of the dipper.

At the same time, the plunger presses a bridge 26 against the contacts 26 and 26 and causes the current to pass by the wire 65 to the upper coil 30* of the solenoid 30. the current passing out through the connection 55. The coil 30 will therefore force down the plunger and will push the piston 6 into its cylinder and force the molten metal into the die under the desired pressure. The metal cools almost immediately;

To restore the parts totheir starting position, the hand switch 51 is thrown in the opposite direction to engage the contact 53. The first effect is to break the circuits in the several solenoids, releasing the several bridges above referred to and thus removing the pressure which was exerted on the piston 6 and other moving parts. The next effect is to pass the current through the coil 26 of the solenoid which actuates the table and to cause the latter to lift its core and to lift the die clear of the dipper. At the end of this stroke, the bridge 26 is brought up to connect the contacts 26 and 26.

This passes the current by the wire 66 through the left hand coil 22 of the solenoid 22, which draws its plunger to the right and moves the closed pair of dies from their position above the melting pot. At the end of this stroke, the plunger of the solenoid 22 brings the bridge 22 into engagement With the contacts 22 and 22 The current then passes through the wire 67 to the left hand coil 16 of the solenoid 16 and draws the plunger of the latter to the right, separating the dies to permit the removal of the casting and, at the end of the stroke, bringing the bridge 16 into engagement with the contacts 16 and 16 This causes the current to pass through the wire 68 and through the lower coil 9 of the dipper-actuating solenoid 9, which lifts the core of the latter and depresses the dipper into the molten metal ready for a new charge. At the end of the stroke, the bridge 9 closes the contacts 9, 9*, allowing the current to pass through the wire 57 thus energizing the coil 30 of the magnet which raises the pressure piston 6 of the dipper, the current passing through the line 57 thence through the coil and out by the connection 55 to the line 56 which goes to the line switch. This lifts the plunger of the solenoid and sucks a charge of molten metal into the dipper.

The control switch may then be shifted to the central position, until the finished article is withdrawn from the die, after which the previous operations will be re peated. The first cycle of operations will be an idle one because the dipper will not take up any metal until the upward movement of the piston 6 takes place, which is at the end of the cycle.

The machine illustrated is of a known type, and it will be understood that the invention may be applied to other usual or suitable designs of die casting machines. Also the solenoid motors illustrated may be of other types and differently arranged. The solenoid 30, for example, which exerts the casting pressure on the molten metal may be mounted in a more remote position with suitable connections for transmitting into the metal inthe dipper the pressure of air compressed by the piston.

The electric devices shown have considerable advantages compared with the use of fluid pressure (steam, air or the like) which has been commonly used heretofore. They give a pressure which is maintained throughout the casting operation and which is uniform at all times and is produced at a comparatively small expense. These devices are also simple and more durable than the fluid devices with their connections and packings which have been heretofore used, and are small enough to be easily mounted on the machine. A great advantage of these electric devices is the possibility of connecting them up by very simple switches so as to perform the several operations in an automatically determined sequence, and such an automatic operation makes it possible to secure a greater output of machines per day, which is of course an important point. The piston 6 in the outer end of the dipper exerts a suction to draw the metal into the dipper with greater force than that of gravity alone, so that it works well even when the metal in the melting pot falls to a low level.

Though We have described with great particularity of detail certain embodiments of our invention, yet it is not to be understood therefrom that the invention is restricted to the particular embodiments I described,

Various modifications thereof in detail and in the arrangement of the parts may be made by those skilled in the art without departure from the invention as defined in the following claims. I

What we claim is 1. A die casting machine having an electric device for exerting a closing stroke on per and a piston in the outer end thereof arranged to suck the metal into the dipper when the latter is in the melting pot.

4. A- die casting machine having a dipper and a piston in the outer end thereof, said dipper being pivotally mounted so as to swing the mouth thereof up against the die or down into the molten metal, said piston being adapted to suck the metal into the dipper through the mouth of the latter when such month is in the molten metal.

In Witness whereof, we have hereunto signed our names.

THOMAS E. MURRAY, JR. HENRY S. HOLMES. 

